Temperature moderated supports for flow tubes

ABSTRACT

The present invention provides a system and method that allows use of the same or similar material as the flow tubes for the supports and without requiring more expensive stainless or higher alloy supports. The disclosure provides one or more temperature moderated support tubes that allow the process fluid in the flow tubes to also pass through the support tubes. The benefit is that the process fluid moderates the temperature of the support tubes and hence the thermal expansion of the support tubes to be relatively consistent with the expansion of the flow tubes of the coil, and further benefits from additional heat transfer area using the support tubes. Thus, the support tubes can be made from the same or similar material as the flow tubes. The ledges/brackets could be also of the same material as the coil material.

CROSS REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO APPENDIX

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention disclosed and taught herein relates generally to temperature controlled supports for flow tubes; and more specifically relates to a system and method of controlling the temperature of supports for flow tubes in environments such as a furnace.

2. Description of the Related Art

Conduits and tubes in which fluid can flow, referred to herein as “flow tubes”, are typically used to transfer heat between a surrounding environment and the fluid inside the flow tubes by transferring energy from a higher temperature to a lower temperature either from the environment to the flow tubes, such as in a furnace, or from the tubes to the environment, such as a heater. The same principles of heating apply with cooling by transferring energy from a lower temperature to a higher temperature and both transfers of energy will generally be referred to herein as “heat transfer.”

The flow tubes are generally in the shape of coils to maximize heat transfer in the environment. Two general types of coils are serpentine and helical. In general, a serpentine coil is made of a flow tube that bends each successive pass of the flow tube in an opposite direction from the preceding pass in an aligned row. A helical coil progressively winds a flow tube in a spiral that is generally circular.

Coils can be oriented horizontally or vertically, and helical coils typically are supported by a set of structural supports running parallel to the axis of the helix. For example, a vertical coil can be supported by supports suspended from a top of a furnace or other structure, or resting on the floor of the structure. A typical arrangement is a set of three or four pipes suspended from the top of the furnace. While the metal temperature of the coiled flow tube remains relatively low due to the internal fluid flow, the supports attain very high temperatures at about the same as the furnace temperatures that are typically in the range of 1600 F (870 C) to 2000 F (1090 C) or more. Hence, the supports are required to be made of high alloy materials to withstand such temperatures for a commercially reasonable lifetime. Brackets or ledges, also made of stainless or higher alloy materials, are welded to the supports typically for each turn of the coil at three or four support locations around the coil periphery. The coil can be held down by U-bolts or other fasteners at these support locations.

FIG. 1 is a cross-sectional side schematic view of a typical support system 2 with brackets for supporting a coil within a differential temperature environment, such as a furnace. A chamber 4 encloses the various tubes used to flow the process fluid. A flow tube 6 having helical coils 8 has an inlet 10 that protrudes through the bottom 18 and an outlet that protrudes through the top 14. Longitudinal supports 16A, 16B (generally, “16”) are coupled to the top 14 for suspending therefrom. The supports 16 are coupled to the coils 8 of the flow tube 6 with brackets 20.

The longitudinal supports thermally expand more longitudinally than the coil, because the longitudinal supports attain higher temperatures and because the supports are made of high alloy materials that typically have higher coefficients of expansion than the coil. Also, the coil typically thermally expands radially more than the supports and can cause radial stress. The connected external piping is typically designed to be flexible to accommodate this coil expansion. The differential expansion causes multiple stresses between the coil and the supports. Without special design allowances and flexibility, the differential expansion can cause failure of the supports, the coil, or both.

Therefore, there remains a need to provide a system of supports and a method for supporting a flow tube within an environment for heat transfer that does not need the more expensive high alloy content than material used for the flow tube, and can be more dimensionally consistent in expansion and contraction with the supported flow tube.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a system and method that allows use of the same or similar material as the flow tubes for the supports and without requiring more is expensive stainless or higher alloy supports. The disclosure provides one or more temperature moderated support tubes that allow the process fluid in the flow tubes to also pass through the support tubes. The benefit is that the process fluid moderates the temperature of the support tubes and hence the thermal expansion of the support tubes to be relatively consistent with the expansion of the flow tubes of the coil, and further benefits from additional heat transfer area using the support tubes. Thus, the support tubes can be made from the same or similar material as the flow tubes. The ledges/brackets could be also of the same material as the coil material.

The disclosure provides a system for flowing process fluid through a flow tube for heat transfer in a chamber, comprising: a flow tube having an internal flow path to flow the process fluid; and a support tube configured to be coupled to the chamber and having an internal flow path to flow the process fluid, the internal flow path of the support tube being fluidicly coupled to the internal flow path of the flow tube and the support tube being mechanically coupled to the flow tube to support the flow tube.

The disclosure provides a method of flowing a process fluid through a flow tube and a support tube for heat transfer in a chamber, comprising: flowing the process fluid through an internal flow path of the support tube; flowing the process fluid through an internal flow path of a flow tube fluidicly coupled to the flow path of the support tube; and flowing the process fluid out of the internal flow path of the flow tube or the support tube.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a cross-sectional side schematic view of a typical support system with brackets for supporting a coil within a differential temperature environment, such as a furnace.

FIG. 2 is a cross-sectional side schematic view of a support system of the present disclosure with a support tube fluidicly coupled and mechanically coupled with a flow tube in a coil within a differential temperature environment, such as a furnace.

FIG. 3 is a flow schematic of a process fluid through a plurality of support is tubes fluidicly coupled to a flow tube in a coil.

FIG. 4A is a schematic of a system having an inlet and an outlet with a plurality of support tubes that are coupled with a flow tube, the support tubes having a peripheral distribution.

FIG. 4B is a schematic of another exemplary system having an inlet and an outlet with a plurality of support tubes that are coupled with a flow tube, the support tubes having a radial distribution.

FIG. 4C is a schematic of another exemplary system having a plurality of inlets and outlets with a plurality of support tubes coupled with a plurality of flow tubes.

DETAILED DESCRIPTION

The Figures described above and the written description of specific structures and functions below are not presented to limit the scope of what Applicants have invented or the scope of the appended claims. Rather, the Figures and written description are provided to teach any person skilled in the art to make and use the inventions for which patent protection is sought. Those skilled in the art will appreciate that not all features of a commercial embodiment of the inventions are described or shown for the sake of clarity and understanding. Persons of skill in this art will also appreciate that the development of an actual commercial embodiment incorporating aspects of the present inventions will require numerous implementation-specific decisions to achieve the developer's ultimate goal for the commercial embodiment. Such implementation-specific decisions may include, and likely are not limited to, compliance with system-related, business-related, government-related and other constraints, which may vary by specific implementation, location and from time to time. While a developer's efforts might be complex and time-consuming in an absolute sense, such efforts would be, nevertheless, a routine undertaking for those of ordinary skill in this art having benefit of this disclosure. It must be understood that the inventions disclosed and taught herein are susceptible to numerous and various modifications and alternative forms. Lastly, the use of a singular term, such as, but not limited to, “a,” is not intended as limiting of the number of items. Also, the use of relational terms, such as, but not limited to, “top,” “bottom,” “left,” “right,” “upper,” “lower,” “down,” “up,” “side,” and the like are used in the written description for clarity in specific reference to the Figures and are not intended to limit the scope of the invention or the appended claims. Where appropriate, elements have been labeled with an “a” or “b” to designate one side of the system or another. When referring generally to such elements, the number without the letter is used. Further, such designations do not limit the number of elements that can be used for that function.

The present invention provides a system and method that allows use of the same or similar material as the flow tubes for the supports and without requiring more expensive stainless or higher alloy supports. The disclosure provides one or more temperature moderated support tubes that allow the process fluid in the flow tubes to also pass through the support tubes. The benefit is that the process fluid moderates the temperature of the support tubes and hence the thermal expansion of the support tubes to be relatively consistent with the expansion of the flow tubes of the coil, and further benefits from additional heat transfer area using the support tubes. Thus, the support tubes can be made from the same or similar material as the flow tubes. The ledges/brackets could be also of the same material as the coil material.

FIG. 2 is a cross-sectional side schematic view of a support system of the present disclosure with a support tube fluidicly coupled and mechanically coupled with a flow tube in a coil within a differential temperature environment, such as a furnace. The system 2 includes at least one flow tube 26 with one or more coils 28. The system 2 can be mounted within a chamber 24, such as a furnace, having a top 36 and a bottom 38. The flow tube 26 includes an internal flow path 27 through which process fluid can flow. The flow tube generally extends through the chamber, such as through the top 36, to connect to other equipment not shown. A support tube 30 can be coupled to the chamber 24, such as suspended from the top 36. The support tube 30 can be oriented in a variety of positions, vertically, horizontally, or angularly, and the above example is non-limiting. The support tube 30 includes an internal flow path 31 through which process fluid can flow.

The support tube 30 is generally fluidicly and mechanically coupled with the flow tube 26. The support tube 30 is fluidicly coupled with the flow tube by coupling the flow path 31 of the support tube with the flow path 27 of the flow tube 26. Thus, the process fluid can flow through both the flow tube 26 and the support tube 30. In at least one embodiment, the process fluid can flow into an inlet 32 through the flow path 31 of the support tube 30 and out of the flow path 27 of the flow tube 26 at an outlet 34. This flow direction provides that the support tube will have the cooler process fluid prior to the process fluid entering the flow tube and becoming heated from the heat in the chamber 24. However, the flow direction can be reversed to flow through the flow tube and then through the support tube. The support tube 30 is also mechanically coupled with the flow tube 26 to support the structure of the flow tube. In at least one example, one or more brackets 40 can extend between the support tube 30 and the coils 28 of the flow tube 26. Other mechanical coupling elements and means can be used, including fastening, welding, adhesively attaching, and other forms of attachment with or without separate elements and directly or indirectly between the support tube 30 and the flow tube 26.

The disclosure thus provides a flow-through support tube that can be cooled (in a heated chamber) with the same process fluid as flows through a flow tube. The coupling of the flow paths of the support tube and the flow tube ensures that the process fluid will flow through the support tube whenever the process fluid flows through the flow tube. The process fluid flowing through both the flow tube and the support tube can reduce a temperature gradient between the support tube and the flow tube that would otherwise exist without the cooling of supports. Less temperature gradients cause less thermal expansion and less stress on the system.

Further, the cooling of the support tube allows the support tube to be made of similar material as the flow tube and can avoid more expensive alloy materials that otherwise would be used for typical high heat resistance without the cooling. The same or similar material of the flow tube as the support tube can lead to the same or similar coefficient of expansion to further reduce stress from thermal expansion between the support tube and the flow tube. Still further, the support tubes provide additional heat transfer area and can help efficiently transfer heat.

While the general use of the system 2 is believed to be particularly useful for heated chambers, such as furnaces, due to the thermal expansion from large temperature gradients (ambient temperatures versus 2000 F (1090 C)), the same principles described above apply to a cooled chamber that provides cooling to the process fluid. The flow paths of the flow tube 28 and support tube 30 can flow the process fluid and receive the energy transfer from a cooled chamber 24. Further, the principles apply to a system in which the process fluid can heat (or cool) the chamber through energy transfer from a heated (or cooled) process fluid.

FIG. 3 is a flow schematic of a process fluid through a plurality of support tubes fluidicly coupled to a flow tube in a coil. In some embodiments, it is advantageous to have a plurality of support tubes that can be disposed about a periphery of the flow tube coils to provide additional support. A header is useful to distribute the incoming process fluid to the plurality of support tubes, and another header can be useful to converge the flow through the support tubes. In the exemplary embodiment of FIG. 3, an inlet 32 of a support tube 30 is fluidicly coupled to a header 44. The header 44 is coupled to a plurality of support tubes 30A, 30B, 30C, 30D (the number can vary) and, in this exemplary flow direction, distributes the process fluid into the support tubes. In turn, the support tubes 30A-30D are coupled to a header 46, which, in this exemplary flow direction, converges the process fluid from the support tubes into a common flow path. The flow can be directed into the flow is tube 26 through the coils 28 and out through the outlet 34. In other embodiments, the flow direction could be reversed, so that the flow is through the flow tube 26 initially, and then the header 46, through the support tubes 30A-30D, into the header 44, and out of the support tube 30.

FIGS. 4A-4C illustrate various arrangements of support tubes around a periphery of one or more flow tubes with various arrangements of headers. The examples are non-limiting and only illustrate some of the options and arrangements possible given the underlying principles disclosed herein. Other flow embodiments can be used, including: reversed flow directions (inlets effectively become outlets and so forth), combinations of radial and peripheral distribution and convergence of flows can be used, and combinations of sets of flow tubes with sets of support tubes that have separate flows from other sets of flow tubes and support tubes are possible and are contemplated in this disclosure.

FIG. 4A is a schematic of a system having an inlet and an outlet with a plurality of support tubes that are coupled with a flow tube, the support tubes having a peripheral distribution. A support tube 30 with an inlet 32 is coupled to a header 44 having header portions 44A, 44C with internal flow paths that are coupled to a header peripheral portion 44E also with an internal flow path. The peripheral portion 44E is coupled to a plurality of support tubes 30A, 30B, 30C, 30D and can supply process fluid peripherally to the support tubes, especially to support tubes 30B, 30D that are peripherally distal from the support tubes 30A, 30C and the header portions 44A, 44C. The support tubes 30A-30D are coupled to another header 46, distal from the header 44. The header 46 includes header portions 46A-46D and a header peripheral portion 46E coupled to the header portions 46A-46D. The header portions 46A-46D are coupled to a connection 48 that is coupled to the flow tube 26. The flow tube 26 has an outlet 34 distal from the connection 48. The support tubes 30A-30D can be coupled with the flow tube 26 for support thereof.

In one embodiment of FIG. 4A, the process fluid can enter the inlet 32 of the support tube 30, flow through the header 44 to distribute the flow into the support tubes 30A-30D. The process fluid can flow through the support tubes 30A-30D into the header 46, through the connection 48 into the flow tube 26 and associated coils 28, and through the outlet 34. Alternatively, the flow directly can be reversed with the same underlying principles described herein.

FIG. 4B is a schematic of another exemplary system having an inlet and an outlet with a plurality of support tubes that are coupled with a flow tube. A support tube 30 with an inlet 32 is coupled to a header 44 having header portions 44A, 44B, 44C that are coupled to a header peripheral portion 44E. The header portions 44A, 44B, 44C can be radially coupled to a plurality of support tubes 30A, 30B, 30C (optionally independently of the header peripheral portion 44E) and can supply process fluid radially to the support tubes. The support tubes 30A-30C can be coupled to another header 46, distal from the header 44. The header 46 includes header portions 46A, 46B, 46C and a header peripheral portion 46E coupled to the header portions 46A-46C. The header portions 46A-46C are coupled to a connection 48 that is coupled to the flow tube 26. The flow tube 26 has an outlet 34 distal from the connection 48. The support tubes 30A-30C can be coupled with the flow tube 26 for support thereof.

In one embodiment of FIG. 4B, the process fluid can enter the inlet 32 of the support tube 30, flow through the header 44 to distribute the flow into the support tubes 30A-30C. The process fluid can flow downwardly through the support tubes 30A-30C into the header 46, through the connection 48 into the flow tube 26 and associated coils 28, and through the outlet 34. Alternatively, the flow directly can be reversed with the same underlying principles described herein.

As an alternative embodiment, the peripheral portion 44E need not have an internal flow path that is coupled to the header portions 44A-44C. The peripheral portion 44E can be only for support without any flow therethrough and can be a solid member.

FIG. 4C is a schematic of another exemplary system having a plurality of inlets and outlets with a plurality of support tubes coupled with a plurality of flow tubes. This embodiment has similar principles as described in other embodiments, but has a plurality of flow tubes 26A, 26B, 26C fluidicly coupled with a plurality of support tubes 30A, 30B, 30C, respectively. One or more flow paths from one or more support tubes 30A-30C can be fluidicly coupled with one or more flow paths through one or more flow tubes 26A-26C, so that a combined flow path of a support tube and a flow tube can independently flow the process fluid without being combined with flow paths of other flow tubes and support tubes. The support tubes 30A-30C can each have an inlet 32A-32C, respectively, and the flow tubes 26A-26C can each have an outlet 34A-34C, respectively. The support tubes can be coupled with the flow tubes to support the flow tubes. Further, one or more support rings 50, 52 at distal portions of the assembly of support tubes and flow tubes can further support the assembly in a direction radial to an axis of the assembly. The support rings may or may not have flow paths.

An alternative embodiment of FIG. 4C is that the process fluids from the inlets 32A-32C could be combined through a flow path in the support ring 50, effectively acting as a header, and then flow through the support tubes 30A-30C, and directly into the respective flow tubes 26A-26C. Further, the support ring 52 would also act as a header for combined flows of the support tubes 30A-30C.

Other and further embodiments utilizing one or more aspects of the inventions described above can be devised without departing from the spirit of Applicant's invention. The embodiments of the system and method for flowing process fluid through one or more support tubes and through one or more flow tubes can be varied. The embodiments of the system and method can be included in combination with each other to produce variations of the disclosed methods and embodiments. The above described examples are nonlimiting and one or more flow paths may be combined with one or more flow paths in the various examples and with other embodiments not specifically noted. Further, the concepts of the flow paths through the support tubes and flow tubes have been explained here within the exemplary context of a heated chamber and can be used with a cooled chamber. Other variations are possible. The disclosed and undisclosed embodiments are not intended to limit or restrict the scope or applicability of the invention conceived of by the Applicant, but rather, in conformity with the patent laws, Applicant intends to fully protect all such modifications and improvements that come within the scope or range of equivalent of the following claims.

Discussion of singular elements can include plural elements and vice-versa. References to at least one item followed by a reference to the item may include one or more items. Unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising,” should be understood to imply the inclusion of at least the stated element or step or group of elements or steps or equivalents thereof, and not the exclusion of a greater numerical quantity or any other element or step or group of elements or steps or equivalents thereof. The device or system may be used in a number of directions and orientations. The term “coupled,” “coupling,” “coupler,” and like terms are used broadly herein and may include any method or device for securing, binding, bonding, fastening, attaching, joining, inserting therein, forming thereon or therein, communicating, or otherwise associating, for example, mechanically, magnetically, electrically, chemically, fluidicly, directly or indirectly with intermediate elements, one or more pieces of members together and may further include without limitation integrally forming one functional member with another in a unity fashion. The coupling may occur in any direction, including rotationally.

The order of steps can occur in a variety of sequences unless otherwise specifically limited. The various steps described herein can be combined with other steps, interlineated with the stated steps, and/or split into multiple steps. Similarly, elements have been described functionally and can be embodied as separate components or can be combined into components having multiple functions. 

1. A system for flowing process fluid through a flow tube for heat transfer in a chamber, comprising: a flow tube having an internal flow path to flow the process fluid therethrough; and a support tube configured to be coupled to the chamber and having an internal flow path to flow the process fluid therethrough, the internal flow path of the support tube being fluidicly coupled to the internal flow path of the flow tube and the support tube being mechanically coupled to the flow tube to support the flow tube.
 2. The system of claim 1, further comprising a plurality of support tubes having an internal flow path to flow the process fluid therethrough, the plurality of support tubes being fluidicly coupled together through a header and the header being fluidicly coupled to the flow tube.
 3. The system of claim 2, further comprising a first header coupled to the plurality of support tubes, a second header coupled to a distal portion of the plurality of support tubes from the first header, and the second header coupled to the flow tube distal from the first header.
 4. The system of claim 2, further comprising a first header coupled to the plurality of support tubes, a second header coupled to a distal portion of the plurality of support tubes from the first header, and the first header coupled to the flow tube distal from the second header.
 5. The system of claim 2, wherein the header is fluidicly coupled in a peripheral direction to one or more of the support tubes.
 6. The system of claim 2, wherein the header is fluidicly coupled in a radial direction to one or more of the support tubes.
 7. The system of claim 2, further comprising a plurality of flow tubes independently coupled to the plurality of support tubes to establish combined flow paths of at least one support tube with at least one flow tube relative to other combined flow paths of other combinations of at least one supports tube and at least one flow tube.
 8. A method of flowing a process fluid through a flow tube and a support tube for heat transfer in a chamber, comprising: flowing the process fluid through an internal flow path of the support tube; flowing the process fluid through an internal flow path of the flow tube fluidicly coupled to the flow path of the support tube; and flowing the process fluid out of the internal flow path of the flow tube or the support tube.
 9. The method of claim 8, wherein a plurality of support tubes having an internal flow path is fluidicly coupled to a header having an internal flow path, and further comprising flowing the process fluid through the flow paths of the plurality of support tubes and the header.
 10. The method of claim 9, further comprising flowing the process fluid through a first header coupled to the plurality of support tubes, flowing the process fluid through a second header coupled to a distal portion of the plurality of support tubes from the first header, and flowing the process fluid through the flow tube coupled to the second header.
 11. The method of claim 9, further comprising flowing the process fluid through a first header coupled to the plurality of support tubes, flowing the process fluid through a second header coupled to a distal portion of the plurality of support tubes from the first header, and flowing the process fluid through a flow tube coupled to the first header.
 12. The method of claim 9, further comprising flowing the process fluid through the header in a peripheral direction.
 13. The method of claim 9, further comprising flowing the process fluid through the header in a radial direction.
 14. The method of claim 9, further comprising a plurality of flow tubes coupled to the plurality of support tubes, and comprising flowing the process fluid through a first flow tube and a first support tube fluidicly coupled to the first tube independently of a process fluid flowing through a second flow tube and a second support tube coupled to the second flow tube. 